Regulators of G protein signaling (RGS) accelerate intrinsic GTP hydrolysis on subunits of trimeric G proteins and play crucial roles in the physiological regulation of G protein-mediated cell signaling. The control mechanisms of the action of RGS proteins per se are poorly clarified, however. We recently showed a physiological mode of action of a RGS protein in cardiac myocytes. The voltagedependent formation of Ca2 calmodulin facilitated the GTPase activity of RGS by an unidentified mechanism… CONTINUE READING